Numerous methods have been suggested and many have been used in an effort to control erosion, and to encourage accretion, of sand and other subsoils non-cohesive when wet, especially in the instance of beaches--and to discourage deposition of (or to displace) undesired sand or soil, especially in channels useful for shipping. Attempts to overcome undesired effects of wave action have usually been unavailing in the long run, sometimes producing the opposite of what was sought and/or other deleterious results. Man has to learn to use nature rather than to fight it in such environmental efforts.
Channel maintenance (or creation) traditionally is accomplished by dredging, repeated whenever current or wave action tends to fill in the channel (frequently). Dredging costs enough the first time, and necessary repetition is an aggravation of expense. Fluidization as an alternative to dredging is also well recognized, noted as long as a century ago by Scott in U.S. Pat. No. 510,713.
However, even such alternative channel clearing and maintenance have relied upon the energy-intensive step of dredging to enable the necessary piping to be buried preparatory to fluidizing use.
The piping placement art is represented by van Steveninck U.S. Pat. No. 3,695,049, in which piping to be buried is supplied with one or more small accompanying pipes to fluidize underlying subsoil "causing the pipeline together with the fluidization pipes to sink into the fluidized seabed." The present inventor has proposed aids to placement of fluidizing piping in his U.S. patent application Ser. No. 465,838 filed Jan. 16, 1990, now U.S. Pat. No. 5,052,857 and has cited additional prior art therein.
The present invention provides improved means and methods for emplacing foraminous piping and means for retaining such piping in place, as for use in non-cohesive soil fluidization for channel maintenance, or use in subsoil stabilization for beach maintenance.